New Harvard Kennedy School faculty member Wolfram Schlenker conducts research on the effect of weather and climate on agricultural yields and global food prices. Schlenker is the Ray A. Goldberg Professor of the Global Food System and taught at Columbia University before joining the Kennedy School. He is also a research associate at the National Bureau of Economic Research and serves on the board of reviewing editors at Science. We caught up with him to learn more about his work.
Q: How does your research and teaching connect to solutions to pressing problems in the world today?
My research is at the intersection of agricultural and environmental economics. I'm trained as an economist and study how climate change affects the global food supply and global food prices. Climate change is shifting much more of the temperature distribution towards extreme heat. One of the things I have been studying and teaching is how to estimate a link between temperatures and agricultural outcomes. And one of the biggest findings is that extreme heat is the key driver.
So, for example, if you look at the variability in corn yields in the United States from year to year, more than half of that variability is explained by looking at how much and for how long temperatures exceed 86 degrees Fahrenheit or 30 degrees Celsius, while disregarding all other temperatures. Extreme heat is the best predictor of corn yields. With climate change, the exposure to extreme heat is projected to go up, and we have to worry that we could see significant reductions in yields.
The 2012 heat wave over the U.S. corn belt saw yields dropping by about 25%. That is troublesome because the United States is by far the largest producer of agricultural staple commodities. It has a much larger market share in the basic commodities than, for example, Saudi Arabia has in oil. So, anything that happens in the United States has huge repercussions for the whole world, especially for the poor. If you are living on one or two dollars a day, it has a real impact if commodity prices triple like they did between 2005 and 2007.
Q: In your own research, have you found anything surprising or particularly striking?
One thing that was very surprising to me, and I think most people don’t recognize, is how big the United States is in terms of agricultural production. Globally, there are four basic staple commodities: corn (some call it maize), wheat, rice, and soybeans. Together, they account for about 70% of the calories that humans consume, either directly or indirectly because they are used to feed livestock. The United States’ market share has been between 25% and 30% over the last 50 years for those commodities, mostly because of its dominant market share in corn and soybeans, which exceed 40% of global production. Since the latter two crops grow in the same geographic area in the Midwest, any weather effect has huge repercussions for the whole world’s food prices.
Q: What are you teaching at the Kennedy School? And what do you want your students to take away from your teaching?
I am very honored to have taken on this endowed professorship in memory of Ray Goldberg, who was a professor here at the School. He brought together a wide variety of stakeholders from business, government, and NGOs to work on solving the world's food problems. In my class BGP-204: Food Policy, we try to bring in those different perspectives and discuss the role of the global food system. We will examine how it can meet the caloric needs of a growing population with higher caloric demands. We will discuss the historical context of food policy and how it has shaped societies, impacted farm economies and agricultural productivity, and how climate change has the potential to negatively affect agricultural productivity. We will analyze food-related programs from economic and political perspectives, specifically focusing on food assistance, nutrition, and consumer protection and information programs.
“One of the things I have been studying and teaching is how to estimate a link between temperatures and agricultural outcomes. And one of the biggest findings is that extreme heat is the key driver.”
Wolfram Schlenker
Q: What else are you looking forward to here at the Kennedy School?
I am particularly excited that the Salata Institute for Climate and Sustainability is housed here at the Kennedy School. It's an initiative that brings together researchers from various fields across campus. I think they are doing amazing work. They are really pushing the boundaries by fostering interdisciplinary policy-relevant work and how we can solve the climate and sustainability crisis together, and I am very excited to be part of this work.
Q: Who or what has inspired you in your work?
My maternal grandfather: he was the first in his family to go to college—his parents had signed him up to become a carpenter, but his teachers convinced my great-grandparents to allow my grandfather to go to university. He studied physics, and many of his children and grandchildren followed in his footsteps, some becoming professors. I wanted to do something completely different. But after working for a while in business consulting, I realized that there was something to it, to being a professor, to studying things in more depth, and to teaching.
So, I followed in the footsteps of my family. I studied physics and engineering for a while and then went into environmental and agricultural economics. Those fields have more in common than many realize. That’s something I’m trying to teach my students in class as well—we can learn a lot by looking across disciplinary boundaries.
Q: What book has made a big impression on you?
One book that had a large impact on me was Al Gore’s book “Earth in the Balance: Ecology and the Human Spirit.” I was, at the time, a graduate student in Germany. I was enrolled in a program that bridges engineering and management science. And I had a very engaged classmate who wanted to come to the United States for one year. He told me, “Wolfram, do something different. Try a different subject.” I had always been curious about environmental economics, and I was interested in the ideas in Al Gore’s book. I had planned to come to the United States for one year only. But then I fell in love with the subject, and never returned to Germany, and went on to complete a PhD in agricultural and resource economics from the University of California, Berkeley, eventually becoming a professor. Had I not read that book, and gone on this journey, I may have led a completely different life.
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Photography by Lydia Rosenberg